Some strange, wibbly wobbly timey wimey thing- there was a glitch where you can make a portal go into a portal and you had infinite portals. Strange stuff- like high on acid sorta. It's fixed now so you can't do it.

i know because i beet portal+portal 2 it is caled a portal bump the portal will just move the uther portal away from it nothin bad but airhit is right thar is a cheat to make a portal go in to a portal